The present invention relates to stent enhancement in fluoroscopic images, and more particularly, to real time stent enhancement on a 2D fluoroscopic scene in order improve visualization of a stent during image-guided interventions.
Stent thrombosis and restenosis are associated with stent under-expansion, which has been shown to be a major risk factor for patients undergoing percutaneous coronary intervention (PCI). During such an intervention, a stent is deployed via a balloon at a location of a lesion inside the coronary artery. This procedure is typically monitored by X-ray fluoroscopy. However, the stent visibility is often low in the fluoroscopic images because the radiation is usually kept to a minimal level and stents are only slightly radiopaque in typical X-ray fluoroscopy. The low visibility of the stent undermines the assessment of the stent implantation outcome, which increases the risk of incomplete stent expansion. Although increasing signal to noise ratio by increasing radiation doses or using stents with radiopaque coatings may result in negative clinical effects, few viable alternative solutions are currently available.
The most reliable method to assess stent expansion is to observe the stent via intravascular Ultrasound (IVUS), in which an Ultrasound transducer is inserted into the target coronary artery via a catheter. However, IVUS requires an invasive procedure and is too expensive to be used by most current clinics in daily practice. Image processing techniques have been proposed to improve the image quality for better stent visibility, but such techniques provide only offline solutions for stent enhancement, which limits the usage of such techniques in clinical settings.